I am trying to sell my 2001 s-10 Blazer, it has been sitting for the past year. I changed the battery and went to get it smogged. Well the smog guy told me I need to put more miles on the vehicle so the sensors will read. I have been driving none stop on country roads (because I cant get it registered without it passing smog). I have tried the GM drive cycle a number of times, (drive at 55 for 3 minutes decelerate to 20 with no brakes, so on and so on...) Every time I take the car back it still reads not ready on the Catalyst column and the secondary air system. I have tried cold starting, letting idle in drive and everything. The smog guy says the computer says everything is fine, it just needs more miles. Well I have put 330 miles on it so far and nothing is working. I am lost. I have no idea what to do. SOMEONE PLEASE HELP ME!!!

 

They can not pass your vehicle until all of the monitors have completed their tests. Apparently you have at least one that is not complete. Take it some place that will check trouble codes for free, (most auto parts stores will do it). Have them look at the "I/M Readiness Status", or it may be called "Monitor Status", (depends on the brand of scan tool). Find out what monitors are incomplete and post them here. Depending on which monitors are incomplete, you may only need to perform one step of the drive cycle.

 

I believe the drive cycle the pcm needs to run all of its tests takes place under all different kinds of driving conditions. This includes stop and go "city" type driving as well as highway type conditions. I know for my 99 4x4 it resets after 4 cycles to operating temp. for the pcm to reset under different driving conditions. I would reset the computer by disconnecting the battery for atleast 15 minutes reconnect it and try running different types of drive cycles. Should happen within 100 miles or less. Phoenix az only requires the obdII style pass/fail test. Not sure where you are located. Hope this helps.